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...a & b as below lines, a<- list(c(1,3),c(1,2),c(2,3)) b<-c(10,20,30) I would like to have a list (like "d") or a vector (like "e") as below. d<-list(c((1+10),(3+10)),c((1+20),(2+20)),c((2+30),(3+30))) e<- c((1+10)+(3+10),(1+20)+(2+20),(2+30)+(3+30)) Thanks, Yongwan Chun

...and A is a sparse matrix in a regular matrix class. A %*% M takes much more time than M %*% A; moreover, t(t(M) %*% t(A)) is much faster than A %*% M with same result. I would like to know how it is possible. Even though I do not have an exact reason, this fact may be helpful to others. Thanks, Yongwan > n <- 1000 > M <- diag(n) - matrix(1/n,n,n) > A <- matrix(rnorm(n*n)>2,n,n) > system.time(M %*% A) [1] 0.10 0.03 0.12 NA NA > system.time(A %*% M) [1] 3.47 0.03 3.50 NA NA > system.time(t(t(M) %*% t(A))) [1] 0.23 0.00 0.23 NA NA

...e really big. Unfortunately the matrices are not symmetric. If anybody know how to get the trace of it, please help me. An example is as below. n <- 2500 a <- matrix(rnorm(n*n),n,n) b <- matrix(rnorm(n*n),n,n) tr1 <- sum(diag(a %*% b)) tr2 <- sum(diag(a %*% b %*% a %*% b)) Thanks, Yongwan Chun

...messages whenever I run 'make all recommended' without modifying 'MkRules' file. I have removed software and reinstalled them several times but I still failed to get it done. The below message is what I got. If anybody gives information, I would appreciate it very much. Thanks, Yongwan ======================= D:\Rsource\R-2.4.0\src\gnuwin32>make all recommended make[1]: `Rpwd.exe' is up to date. make[4]: Nothing to be done for `svnonly'. installing C headers make[2]: `all' is up to date. make[2]: `libRblas.dll.a' is up to date. make[5]: Nothing to be done for...

...However, this option sets the last element of a factor as -1. For example, if I have a factor which has 5 elements and want to use the "contr.sum" option, the 5th elements is always set to -1. I want set -1 to other element such as 1st or 2nd. Is it possible? Thank you in advance. Yongwan Chun [[alternative HTML version deleted]]